Heat transfer oils should never be used above their auto ignition temperature (AIT). AIT is the temperature at which the fluid will ignite spontaneously in contact with air. Highly paraffinic heat transfer oils such as Caloria HT43, Mobiltherm 603, and Duratherm 630 have AITs of 632° F., 670° F., and 693° F., respectively. These known heat transfer oils are made with highly refined, severely hydrotreated, petroleum-based paraffin oils that do not have the high viscosity index and preferred molecular composition that are desired. Conventional heat transfer oils made by Chevron using petroleum derived neutral oils have AIT's of approximately 599° F. A heat transfer oil, made using a base oil made from a waxy feed, and having a higher auto ignition temperature and higher viscosity index is desired; and processes to make and use it are also desired.